It is desired to reduce energy consumption in railway systems. Several methods are known that reduce energy during an operation of the railway systems. However, the conventional methods generally use static models, or only consider energy efficiency of the individual trains. For example, various run curve optimization methods can reduce energy consumption of the train. Regenerative braking can provide additional energy for the train. Although the conventional methods can increase energy efficiency, those methods do not consider global optimization of the operation of the railway system, and do not minimize total energy consumption.
Further, there are times when amount of available regenerated energy exceeds the demand from other trains and is consequently wasted in the absence of energy storage devices. The use of such energy storage devices in conjunction with optimization is necessary to further reduce energy consumption. Also, locomotive manufacturers are considering locomotives equipped with on-board batteries to store the regenerated energy from batteries.
For example, U.S. Application 20050000386 describes a railway car drive system for accelerating and deaccelerating a train by operating a driving motor, and to improve the power efficiency of the drive system, and recovering the generative power to reduce the load borne by the braking system, and to improve the safety and reliability of the railway car drive system.
U.S. Application 20060005738 describes power generation capability through a traction motor linked to a driving wheel of a train. A controller selectively operates the traction motor in a motoring mode, a coasting mode, or a dynamic braking mode. In the dynamic braking mode, electrical energy is transmitted to an electrical energy storage system. The controller receives control commands from an external control source indicating the operating mode for a particular period of time.
Similarly, U.S. Pat. No. 7,940,016 relates to generative braking methods for a locomotive. Four methods for recovering energy from generative braking and for transferring the energy to energy storage system are disclosed.
U.S. Pat. No. 7,430,967 is concerned with control of locomotive which has on-board energy storage device and can operate either on energy supplied from storage device or from conventional energy sources.
U.S. Pat. No. 7,715,958 relates to the creation of a database of historical information of energy requirements and regenerated energy available from trains along a particular railroad. This historical information is imagined to be used in performing the energy storage control as prediction for future energy demands.
U.S. Pat. No. 8,538,611 describes the multi-level optimization of the railway system such as at the infrastructure, track-level and locomotive level and coordinating amongst the different levels for optimized operation. This work does not consider the case of track-side energy storage devices and coordination of such devices in conjunction
For example, the related application Ser. No. 13/803,857 considers the optimization of substation voltages to minimize the energy consumption in railways. Detailed conditional models for voltage controlled substations and decelerating trains were considered.
Accordingly, it is desired to provide a system and a method for optimizing energy consumption so that the total power provided by the grid to the railway system is minimized, while the energy demand of the railway system is satisfied.